Speed-defined torque control

Abstract

Motors, such as DC motors, and methods and systems for operating a motor, are described. The motor is optionally an electronically commutated motor. The motor comprises one or more electromagnets and a controller device to control the electromagnets. The controller device is configured to calibrate the motor operation in a desired installation to determine the torque needed to achieve a desired operating speed by causing the motor to ramp up to the desired speed, measuring an electric current needed to operate the motor at the desired speed, and setting a value corresponding to a first speed tap using the measured electric current. The controller device is configured to operate the motor in a substantially constant torque mode using the set value at least after the completion of the calibration operation. The motor may be configured for use in a ventilation system, such as an HVACR system.

What is claimed is: 
     
       1. An electronically commutated motor, comprising:
 one or more electromagnets; and 
 a controller device to control the electromagnets, the controller device configured to calibrate operation of the motor in a desired installation by:
 causing the electronically commutated motor to ramp up to a first desired speed; 
 monitoring the electronically commutated motor to determine if it has reached the first desired speed; 
 measuring an electric current needed to operate the electronically commutated motor at the first desired speed, wherein the electric current corresponds to a torque needed to maintain the electronically commutated motor at the first desired speed in the desired installation; and 
 setting a value corresponding to a first speed tap using the measured electric current, 
 wherein the controller device is configured to operate the electronically commutated motor in a substantially constant torque mode using the set value at least after the completion of the calibration operation. 
 
 
     
     
       2. The electronically commutated motor as defined in  claim 1 ,
 wherein the electronically commutated motor is operated in a constant speed mode when the electric current needed to operate the electronically commutated motor at the first desired speed is measured, and 
 wherein the controller device is configured to subsequently operate the electronically commutated motor in the constant torque mode using the set value. 
 
     
     
       3. The electronically commutated motor as defined in  claim 1 , wherein the first speed tap is the only speed tap of the electronically commutated motor to which power is applied during the calibration operation, and
 wherein the controller device is further configured to set a value for a second speed tap as a percentage of an application rated torque associated with the first speed tap. 
 
     
     
       4. The electronically commutated motor as defined in  claim 1 , wherein the electronically commutated motor has a rated maximum horsepower and wherein the controller device is configured to operate the electronically commutated motor at less than the rated maximum horsepower based at least in part on the measured electric current. 
     
     
       5. The electronically commutated motor as defined in  claim 1 , wherein the electronically commutated motor has a rated maximum torque and wherein the controller device is configured to operate the electronically commutated motor at less than the rated maximum torque based at least in part on the measured electric current. 
     
     
       6. The electronically commutated motor as defined in  claim 1 , wherein the controller device is configured to initiate the calibration at least partly in response to a command being received from a thermostat, wherein the electronically commutated motor does not have a separate physical control for initiating calibration. 
     
     
       7. The electronically commutated motor as defined in  claim 1 , wherein the controller device is configured to initiate the calibration by applying power to the first speed tap. 
     
     
       8. The electronically commutated motor as defined in  claim 1 , wherein the electronically commutated motor is configured to be installed in a ventilation system to cause airflow. 
     
     
       9. The electronically commutated motor as defined in  claim 1 , wherein the electronically commutated motor is configured to be a drop-in replacement for a permanent-split capacitor motor. 
     
     
       10. A method sizing a motor torque, comprising:
 installing a first motor having a first speed tap; 
 applying power to the first speed tap; 
 causing the first motor to ramp up to a first commanded speed and a calibration process to be initiated, the calibration process comprising:
 causing sufficient motor torque to be produced to hold the first commanded speed substantially constant for a first period of time; 
 determining a value corresponding to a torque needed to hold the first motor substantially constant at the first commanded speed; 
 storing the value corresponding to the torque needed to hold the first motor substantially constant at the first commanded speed; and 
 
 operating the first motor in a constant torque mode based upon the stored value. 
 
     
     
       11. The method as defined in  claim 10 , wherein the value corresponding to the torque needed to hold the speed substantially constant corresponds to a current used to drive a coil of the first motor when holding the first motor substantially constant at the commanded speed. 
     
     
       12. The method as defined in  claim 11 , the method further comprising:
 setting the value as the value for the first speed tap of the first motor; 
 setting a value for a second speed tap of the first motor based at least on the value for the first speed tap, the value for the second speed tap corresponding to a current needed to hold the first motor substantially constant at a second speed. 
 
     
     
       13. The method as defined in  claim 10 , wherein the calibration process is initiated in response to a thermostat setting. 
     
     
       14. The method as defined in  claim 10 , the method further comprising removing a second motor prior to installing the first motor, wherein the first motor is used to replace the second motor, and wherein the first motor is an electronically commutated motor and the second motor is a permanent-split capacitor motor, wherein installing the first motor further comprises connecting all wiring previously connected to terminals of the second motor to the first motor. 
     
     
       15. The method as defined in  claim 10 , the method further comprising resetting the value by applying a voltage to at least two speed taps of the first motor at the same time. 
     
     
       16. The method as defined in  claim 10 , wherein the first speed tap is a highest speed tap of the first motor, wherein the first motor includes a plurality of speed taps. 
     
     
       17. The method as defined in  claim 10 , wherein the first motor is installed in a ventilation system. 
     
     
       18. The method as defined in  claim 10 , wherein a user takes no manual action with respect to the calibration process during the calibration process. 
     
     
       19. A controller configured to control operation of a motor, the controller comprising:
 a computing device: 
 non-transitory memory that stores program instructions, that when executed by the computing device are configured to perform operations comprising:
 calibrating the motor for a given installation by:
 at least partly causing the motor to operate at a first desired speed; 
 determining a value corresponding to a torque needed to operate the motor at the first desired speed; 
 storing the value corresponding to the torque needed to operate the motor at the first desired speed in association with a first speed tap of the motor; and 
 
 
 at least after completion of the calibration, operating the motor in a substantially constant torque mode using the stored value. 
 
     
     
       20. The controller as defined in  claim 19 , the operations further comprising measuring an electric current corresponding to the torque needed to operate the motor at the first desired speed, wherein the determined value is determined based at least in part on the measured electric current. 
     
     
       21. The controller as defined in  claim 20 ,
 wherein the motor is operated in a constant speed mode when the electric current corresponding to the torque needed to operate the motor at the first desired speed is measured, and 
 wherein the controller is configured to subsequently operate the motor in the constant torque mode using the stored value. 
 
     
     
       22. The controller as defined in  claim 19 , wherein the controller is further configured to set a value for a second speed tap by scaling an application rated torque associated with the first speed tap. 
     
     
       23. The controller as defined in  claim 19 , wherein the motor has a rated maximum horsepower and wherein the controller is configured to operate the motor in a range of the rated maximum horsepower to less than the rated maximum horsepower based at least in part on the stored value. 
     
     
       24. The controller as defined in  claim 19 , wherein the motor has a rated maximum torque and wherein the controller is configured to operate the motor at less than the rated maximum torque based at least in part on the stored value. 
     
     
       25. The controller as defined in  claim 19 , wherein the controller is configured to initiate the calibration at least partly in response to a command being received from a thermostat, wherein the motor does not have a separate physical control for initiating calibration. 
     
     
       26. The controller as defined in  claim 19 , wherein the controller is configured to initiate the calibration by applying power to the first speed tap. 
     
     
       27. The controller as defined in  claim 19 , wherein the controller is integral to the motor. 
     
     
       28. The controller as defined in  claim 19 , wherein the motor is an electronically commutated motor.